One of the biggest reasons to use these hitches is because they can reduce trailer sway.
Trailer sway can be caused by improper weight distribution, tight turns, crosswinds, and underinflated tires. However, a weight distribution hitch lowers this risk.
Your vehicle's lifespan will be increased with a good RV weight distribution hitch. You'll also enjoy better fuel economy, a lower risk of tire blowouts, and fewer trips to the mechanic.
You might have heard that a weight distribution hitch increases your maximum towing capacity. This isn't true, but it's easy to see why people think that.
It would be more accurate to say that an RV weight distribution hitch helps you safely reach your vehicle's maximum towing capacity.
However, you should never go over this limit because it's been set for a reason. If you try to overload your tow vehicle, you can permanently damage it.
This isn't the case in every state, but some areas make it illegal to tow an RV without a state-approved hitch. Every state has its own laws for vehicles and RVs, so look up the specific rules in your state before you make a decision.